小麦白粉病严重度与植株生理性状及产量损失的关系

为了探讨植株生理危害及产量损失与小麦白粉病病害等级间的关系,以不同抗性的小麦品种为材料,分析了白粉病菌侵染后小麦植株叶绿素含量、水分含量、氮含量、叶面积指数及产量的变化。结果表明,两个不同抗性的小麦品种随着病情指数的增加,植株叶绿素含量、水分含量、氮含量、叶面积指数均表现下降趋势,白粉病对易感品种偃展4110危害较重,对中抗品种周麦18危害较轻。通过计算各生理指标损失指数发现,其与病害等级间的相关性显著高于生理指标原始测定值(水分含量除外)与病害等级间的相关性。随着接种压力的增大,病情严重度增加,小麦产量及产量因子均表现降低趋势,其中对千粒重危害最严重。利用病害累积指数能较好地预测产量损失状况,减轻生育时期和品种间差异对预测模型的影响,千粒重和产量损失方程的决定系数分别为0.891和0.852。这表明,通过田间植株病情指数动态调查,可以准确预测千粒重下降和产量损失状况。

Relationship of Physiological Indexes and Yield Loss to Severity Level of Wheat Powdery Mildew

The changes of chlorophyll contents, water contents, nitrogen content, leaf area index and yield during powdery mildew infection were studied, and relationships of physiological traits and yield loss to disease index in winter wheat were discussed in this paper. Two types of cultivars with different kinds of resistance on powdery mildew were used under field experiments conditions in the growing seasons of 2009-2010. The results show that the chlorophyll content, water content, nitrogen content and leaf area index of two different resistant varieties of wheat all performed the same declining trend, the powdery mildew damage of the susceptible variety Yanzhan 4110 is heavy, however, the medium resistant variety Zhoumai 18 is slighter. The significant correlation between the levels of powdery mildew disease is significantly higher than the original physiological indexes determination value except for moisture content with calculating harm index of physiological indexes. The severity of disease is increasing with the pressure of vaccination increasing, and the grain yield and its factors takes on the reduced trends, with seriously damage of thousand grain weight. The cumulative value of diseases index from anthesis to specific day were highly correlated with yield and grain weight across grain filling, and diseases accumulated index could well evaluate yield loss, with 0.891 and 0.852 of the coefficients of determination for linear correlations, with reducing the influence of the growth period and varieties on the prediction models. The above results show that investigating dynamic plant disease index in field can accurately estimate grain weight and yield loss.